Abstract:

Water samples were collected, over a nine months period beginning in May 1988, from eleven depths in an 80m water column 10km off shore from Davis station, Antarctica. The samples were analysised for Dissolved Free Amino Acids (DFAAs) by HPLC used pre-column OPA derivatisation. The variation of concentration of total DFAAs were between 19nmol/dm3 and 302 nmol / dm3 during the year and the highest concentration was occurred in 23 November. The annual bloom of the prymnesiophyte alga Phaeocystis Pouchetii occurred, associted with the bloom, the concentration of Dimethyl Sulfide and Acrylic acid were rising in December. However, the concentration of DFAAs was declining with bloom of Phaeocystis Pouchetii. It is suggested that the growth of Phaeocystis Pouchetii, either by direct uptake and/ or indirectly by uptake from the associated quickly growth bacterial populations, reduced the DFAAs concentration to lower level.